When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
Solve 9a + 4a = -a + 9z - 9 for a in terms of z.
| z + 1\(\frac{1}{5}\) | |
| -\(\frac{1}{11}\)z + \(\frac{6}{11}\) | |
| \(\frac{1}{2}\)z - \(\frac{9}{10}\) | |
| -z - 1\(\frac{3}{4}\) |